/*
 * Copyright 2000-2017 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 */
package qunar.tc.decompiler.modules.decompiler.exps;

import qunar.tc.decompiler.code.CodeConstants;
import qunar.tc.decompiler.main.collectors.BytecodeMappingTracer;
import qunar.tc.decompiler.modules.decompiler.ExprProcessor;
import qunar.tc.decompiler.modules.decompiler.vars.CheckTypesResult;
import qunar.tc.decompiler.struct.gen.VarType;
import qunar.tc.decompiler.struct.match.IMatchable;
import qunar.tc.decompiler.struct.match.MatchEngine;
import qunar.tc.decompiler.struct.match.MatchNode;
import qunar.tc.decompiler.util.InterpreterUtil;
import qunar.tc.decompiler.util.ListStack;
import qunar.tc.decompiler.util.TextBuffer;

import java.util.*;

public class FunctionExprent extends Exprent {

    public static final int FUNCTION_ADD = 0;
    public static final int FUNCTION_SUB = 1;
    public static final int FUNCTION_MUL = 2;
    public static final int FUNCTION_DIV = 3;

    public static final int FUNCTION_AND = 4;
    public static final int FUNCTION_OR = 5;
    public static final int FUNCTION_XOR = 6;

    public static final int FUNCTION_REM = 7;

    public static final int FUNCTION_SHL = 8;
    public static final int FUNCTION_SHR = 9;
    public static final int FUNCTION_USHR = 10;

    public static final int FUNCTION_BIT_NOT = 11;
    public static final int FUNCTION_BOOL_NOT = 12;
    public static final int FUNCTION_NEG = 13;

    public final static int FUNCTION_I2L = 14;
    public final static int FUNCTION_I2F = 15;
    public final static int FUNCTION_I2D = 16;
    public final static int FUNCTION_L2I = 17;
    public final static int FUNCTION_L2F = 18;
    public final static int FUNCTION_L2D = 19;
    public final static int FUNCTION_F2I = 20;
    public final static int FUNCTION_F2L = 21;
    public final static int FUNCTION_F2D = 22;
    public final static int FUNCTION_D2I = 23;
    public final static int FUNCTION_D2L = 24;
    public final static int FUNCTION_D2F = 25;
    public final static int FUNCTION_I2B = 26;
    public final static int FUNCTION_I2C = 27;
    public final static int FUNCTION_I2S = 28;

    public final static int FUNCTION_CAST = 29;
    public final static int FUNCTION_INSTANCEOF = 30;

    public final static int FUNCTION_ARRAY_LENGTH = 31;

    public final static int FUNCTION_IMM = 32;
    public final static int FUNCTION_MMI = 33;

    public final static int FUNCTION_IPP = 34;
    public final static int FUNCTION_PPI = 35;

    public final static int FUNCTION_IIF = 36;

    public final static int FUNCTION_LCMP = 37;
    public final static int FUNCTION_FCMPL = 38;
    public final static int FUNCTION_FCMPG = 39;
    public final static int FUNCTION_DCMPL = 40;
    public final static int FUNCTION_DCMPG = 41;

    public static final int FUNCTION_EQ = 42;
    public static final int FUNCTION_NE = 43;
    public static final int FUNCTION_LT = 44;
    public static final int FUNCTION_GE = 45;
    public static final int FUNCTION_GT = 46;
    public static final int FUNCTION_LE = 47;

    public static final int FUNCTION_CADD = 48;
    public static final int FUNCTION_COR = 49;

    public static final int FUNCTION_STR_CONCAT = 50;

    private static final VarType[] TYPES = {
            VarType.VARTYPE_LONG,
            VarType.VARTYPE_FLOAT,
            VarType.VARTYPE_DOUBLE,
            VarType.VARTYPE_INT,
            VarType.VARTYPE_FLOAT,
            VarType.VARTYPE_DOUBLE,
            VarType.VARTYPE_INT,
            VarType.VARTYPE_LONG,
            VarType.VARTYPE_DOUBLE,
            VarType.VARTYPE_INT,
            VarType.VARTYPE_LONG,
            VarType.VARTYPE_FLOAT,
            VarType.VARTYPE_BYTE,
            VarType.VARTYPE_CHAR,
            VarType.VARTYPE_SHORT
    };

    private static final String[] OPERATORS = {
            " + ",
            " - ",
            " * ",
            " / ",
            " & ",
            " | ",
            " ^ ",
            " % ",
            " << ",
            " >> ",
            " >>> ",
            " == ",
            " != ",
            " < ",
            " >= ",
            " > ",
            " <= ",
            " && ",
            " || ",
            " + "
    };

    private static final int[] PRECEDENCE = {
            3,   // FUNCTION_ADD
            3,   // FUNCTION_SUB
            2,   // FUNCTION_MUL
            2,   // FUNCTION_DIV
            7,   // FUNCTION_AND
            9,   // FUNCTION_OR
            8,   // FUNCTION_XOR
            2,   // FUNCTION_REM
            4,   // FUNCTION_SHL
            4,   // FUNCTION_SHR
            4,   // FUNCTION_USHR
            1,   // FUNCTION_BIT_NOT
            1,   // FUNCTION_BOOL_NOT
            1,   // FUNCTION_NEG
            1,   // FUNCTION_I2L
            1,   // FUNCTION_I2F
            1,   // FUNCTION_I2D
            1,   // FUNCTION_L2I
            1,   // FUNCTION_L2F
            1,   // FUNCTION_L2D
            1,   // FUNCTION_F2I
            1,   // FUNCTION_F2L
            1,   // FUNCTION_F2D
            1,   // FUNCTION_D2I
            1,   // FUNCTION_D2L
            1,   // FUNCTION_D2F
            1,   // FUNCTION_I2B
            1,   // FUNCTION_I2C
            1,   // FUNCTION_I2S
            1,   // FUNCTION_CAST
            6,   // FUNCTION_INSTANCEOF
            0,   // FUNCTION_ARRAY_LENGTH
            1,   // FUNCTION_IMM
            1,   // FUNCTION_MMI
            1,   // FUNCTION_IPP
            1,   // FUNCTION_PPI
            12,  // FUNCTION_IFF
            -1,  // FUNCTION_LCMP
            -1,  // FUNCTION_FCMPL
            -1,  // FUNCTION_FCMPG
            -1,  // FUNCTION_DCMPL
            -1,  // FUNCTION_DCMPG
            6,   // FUNCTION_EQ = 41;
            6,   // FUNCTION_NE = 42;
            5,   // FUNCTION_LT = 43;
            5,   // FUNCTION_GE = 44;
            5,   // FUNCTION_GT = 45;
            5,   // FUNCTION_LE = 46;
            10,  // FUNCTION_CADD = 47;
            11,  // FUNCTION_COR = 48;
            3    // FUNCTION_STR_CONCAT = 49;
    };

    private static final Set<Integer> ASSOCIATIVITY = new HashSet<>(Arrays.asList(
            FUNCTION_ADD, FUNCTION_MUL, FUNCTION_AND, FUNCTION_OR, FUNCTION_XOR, FUNCTION_CADD, FUNCTION_COR, FUNCTION_STR_CONCAT));

    private int funcType;
    private VarType implicitType;
    private final List<Exprent> lstOperands;

    public FunctionExprent(int funcType, ListStack<Exprent> stack, Set<Integer> bytecodeOffsets) {
        this(funcType, new ArrayList<Exprent>(), bytecodeOffsets);

        if (funcType >= FUNCTION_BIT_NOT && funcType <= FUNCTION_PPI && funcType != FUNCTION_CAST && funcType != FUNCTION_INSTANCEOF) {
            lstOperands.add(stack.pop());
        } else if (funcType == FUNCTION_IIF) {
            throw new RuntimeException("no direct instantiation possible");
        } else {
            Exprent expr = stack.pop();
            lstOperands.add(stack.pop());
            lstOperands.add(expr);
        }
    }

    public FunctionExprent(int funcType, List<Exprent> operands, Set<Integer> bytecodeOffsets) {
        super(EXPRENT_FUNCTION);
        this.funcType = funcType;
        this.lstOperands = operands;

        addBytecodeOffsets(bytecodeOffsets);
    }

    public FunctionExprent(int funcType, Exprent operand, Set<Integer> bytecodeOffsets) {
        this(funcType, new ArrayList<Exprent>(1), bytecodeOffsets);
        lstOperands.add(operand);
    }

    @Override
    public VarType getExprType() {
        VarType exprType = null;

        if (funcType <= FUNCTION_NEG || funcType == FUNCTION_IPP || funcType == FUNCTION_PPI || funcType == FUNCTION_IMM || funcType == FUNCTION_MMI) {
            VarType type1 = lstOperands.get(0).getExprType();
            VarType type2 = null;
            if (lstOperands.size() > 1) {
                type2 = lstOperands.get(1).getExprType();
            }

            switch (funcType) {
                case FUNCTION_IMM:
                case FUNCTION_MMI:
                case FUNCTION_IPP:
                case FUNCTION_PPI:
                    exprType = implicitType;
                    break;
                case FUNCTION_BOOL_NOT:
                    exprType = VarType.VARTYPE_BOOLEAN;
                    break;
                case FUNCTION_SHL:
                case FUNCTION_SHR:
                case FUNCTION_USHR:
                case FUNCTION_BIT_NOT:
                case FUNCTION_NEG:
                    exprType = getMaxVarType(new VarType[]{type1});
                    break;
                case FUNCTION_ADD:
                case FUNCTION_SUB:
                case FUNCTION_MUL:
                case FUNCTION_DIV:
                case FUNCTION_REM:
                    exprType = getMaxVarType(new VarType[]{type1, type2});
                    break;
                case FUNCTION_AND:
                case FUNCTION_OR:
                case FUNCTION_XOR:
                    if (type1.type == CodeConstants.TYPE_BOOLEAN & type2.type == CodeConstants.TYPE_BOOLEAN) {
                        exprType = VarType.VARTYPE_BOOLEAN;
                    } else {
                        exprType = getMaxVarType(new VarType[]{type1, type2});
                    }
            }
        } else if (funcType == FUNCTION_CAST) {
            exprType = lstOperands.get(1).getExprType();
        } else if (funcType == FUNCTION_IIF) {
            Exprent param1 = lstOperands.get(1);
            Exprent param2 = lstOperands.get(2);
            VarType supertype = VarType.getCommonSupertype(param1.getExprType(), param2.getExprType());
            if (param1.type == Exprent.EXPRENT_CONST && param2.type == Exprent.EXPRENT_CONST &&
                    supertype.type != CodeConstants.TYPE_BOOLEAN && VarType.VARTYPE_INT.isSuperset(supertype)) {
                exprType = VarType.VARTYPE_INT;
            } else {
                exprType = supertype;
            }
        } else if (funcType == FUNCTION_STR_CONCAT) {
            exprType = VarType.VARTYPE_STRING;
        } else if (funcType >= FUNCTION_EQ || funcType == FUNCTION_INSTANCEOF) {
            exprType = VarType.VARTYPE_BOOLEAN;
        } else if (funcType >= FUNCTION_ARRAY_LENGTH) {
            exprType = VarType.VARTYPE_INT;
        } else {
            exprType = TYPES[funcType - FUNCTION_I2L];
        }

        return exprType;
    }

    @Override
    public int getExprentUse() {
        if (funcType >= FUNCTION_IMM && funcType <= FUNCTION_PPI) {
            return 0;
        } else {
            int ret = Exprent.MULTIPLE_USES | Exprent.SIDE_EFFECTS_FREE;
            for (Exprent expr : lstOperands) {
                ret &= expr.getExprentUse();
            }
            return ret;
        }
    }

    @Override
    public CheckTypesResult checkExprTypeBounds() {
        CheckTypesResult result = new CheckTypesResult();

        Exprent param1 = lstOperands.get(0);
        VarType type1 = param1.getExprType();
        Exprent param2 = null;
        VarType type2 = null;

        if (lstOperands.size() > 1) {
            param2 = lstOperands.get(1);
            type2 = param2.getExprType();
        }

        switch (funcType) {
            case FUNCTION_IIF:
                VarType supertype = getExprType();
                result.addMinTypeExprent(param1, VarType.VARTYPE_BOOLEAN);
                result.addMinTypeExprent(param2, VarType.getMinTypeInFamily(supertype.typeFamily));
                result.addMinTypeExprent(lstOperands.get(2), VarType.getMinTypeInFamily(supertype.typeFamily));
                break;
            case FUNCTION_I2L:
            case FUNCTION_I2F:
            case FUNCTION_I2D:
            case FUNCTION_I2B:
            case FUNCTION_I2C:
            case FUNCTION_I2S:
                result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
                result.addMaxTypeExprent(param1, VarType.VARTYPE_INT);
                break;
            case FUNCTION_IMM:
            case FUNCTION_IPP:
            case FUNCTION_MMI:
            case FUNCTION_PPI:
                result.addMinTypeExprent(param1, implicitType);
                result.addMaxTypeExprent(param1, implicitType);
                break;
            case FUNCTION_ADD:
            case FUNCTION_SUB:
            case FUNCTION_MUL:
            case FUNCTION_DIV:
            case FUNCTION_REM:
            case FUNCTION_SHL:
            case FUNCTION_SHR:
            case FUNCTION_USHR:
            case FUNCTION_LT:
            case FUNCTION_GE:
            case FUNCTION_GT:
            case FUNCTION_LE:
                result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
            case FUNCTION_BIT_NOT:
                // case FUNCTION_BOOL_NOT:
            case FUNCTION_NEG:
                result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
                break;
            case FUNCTION_AND:
            case FUNCTION_OR:
            case FUNCTION_XOR:
            case FUNCTION_EQ:
            case FUNCTION_NE: {
                if (type1.type == CodeConstants.TYPE_BOOLEAN) {
                    if (type2.isStrictSuperset(type1)) {
                        result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
                    } else { // both are booleans
                        boolean param1_false_boolean =
                                type1.isFalseBoolean() || (param1.type == Exprent.EXPRENT_CONST && !((ConstExprent) param1).hasBooleanValue());
                        boolean param2_false_boolean =
                                type1.isFalseBoolean() || (param2.type == Exprent.EXPRENT_CONST && !((ConstExprent) param2).hasBooleanValue());

                        if (param1_false_boolean || param2_false_boolean) {
                            result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
                            result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
                        }
                    }
                } else if (type2.type == CodeConstants.TYPE_BOOLEAN) {
                    if (type1.isStrictSuperset(type2)) {
                        result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
                    }
                }
            }
        }

        return result;
    }

    @Override
    public List<Exprent> getAllExprents() {
        return new ArrayList<>(lstOperands);
    }

    @Override
    public Exprent copy() {
        List<Exprent> lst = new ArrayList<>();
        for (Exprent expr : lstOperands) {
            lst.add(expr.copy());
        }
        FunctionExprent func = new FunctionExprent(funcType, lst, bytecode);
        func.setImplicitType(implicitType);

        return func;
    }

    @Override
    public boolean equals(Object o) {
        if (o == this) return true;
        if (!(o instanceof FunctionExprent)) return false;

        FunctionExprent fe = (FunctionExprent) o;
        return funcType == fe.getFuncType() &&
                InterpreterUtil.equalLists(lstOperands, fe.getLstOperands()); // TODO: order of operands insignificant
    }

    @Override
    public void replaceExprent(Exprent oldExpr, Exprent newExpr) {
        for (int i = 0; i < lstOperands.size(); i++) {
            if (oldExpr == lstOperands.get(i)) {
                lstOperands.set(i, newExpr);
            }
        }
    }

    @Override
    public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
        tracer.addMapping(bytecode);

        if (funcType <= FUNCTION_USHR) {
            return wrapOperandString(lstOperands.get(0), false, indent, tracer)
                    .append(OPERATORS[funcType])
                    .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
        }

        // try to determine more accurate type for 'char' literals
        if (funcType >= FUNCTION_EQ) {
            if (funcType <= FUNCTION_LE) {
                Exprent left = lstOperands.get(0);
                Exprent right = lstOperands.get(1);

                if (right.type == EXPRENT_CONST) {
                    ((ConstExprent) right).adjustConstType(left.getExprType());
                } else if (left.type == EXPRENT_CONST) {
                    ((ConstExprent) left).adjustConstType(right.getExprType());
                }
            }

            return wrapOperandString(lstOperands.get(0), false, indent, tracer)
                    .append(OPERATORS[funcType - FUNCTION_EQ + 11])
                    .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
        }

        switch (funcType) {
            case FUNCTION_BIT_NOT:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("~");
            case FUNCTION_BOOL_NOT:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("!");
            case FUNCTION_NEG:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("-");
            case FUNCTION_CAST:
                return lstOperands.get(1).toJava(indent, tracer).enclose("(", ")").append(wrapOperandString(lstOperands.get(0), true, indent, tracer));
            case FUNCTION_ARRAY_LENGTH:
                Exprent arr = lstOperands.get(0);

                TextBuffer res = wrapOperandString(arr, false, indent, tracer);
                if (arr.getExprType().arrayDim == 0) {
                    VarType objArr = VarType.VARTYPE_OBJECT.resizeArrayDim(1); // type family does not change
                    res.enclose("((" + ExprProcessor.getCastTypeName(objArr) + ")", ")");
                }
                return res.append(".length");
            case FUNCTION_IIF:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer)
                        .append(" ? ")
                        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
                        .append(" : ")
                        .append(wrapOperandString(lstOperands.get(2), true, indent, tracer));
            case FUNCTION_IPP:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("++");
            case FUNCTION_PPI:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("++");
            case FUNCTION_IMM:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("--");
            case FUNCTION_MMI:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("--");
            case FUNCTION_INSTANCEOF:
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).append(" instanceof ").append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
            case FUNCTION_LCMP: // shouldn't appear in the final code
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__lcmp__(")
                        .append(", ")
                        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
                        .append(")");
            case FUNCTION_FCMPL: // shouldn't appear in the final code
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__fcmpl__(")
                        .append(", ")
                        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
                        .append(")");
            case FUNCTION_FCMPG: // shouldn't appear in the final code
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__fcmpg__(")
                        .append(", ")
                        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
                        .append(")");
            case FUNCTION_DCMPL: // shouldn't appear in the final code
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__dcmpl__(")
                        .append(", ")
                        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
                        .append(")");
            case FUNCTION_DCMPG: // shouldn't appear in the final code
                return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__dcmpg__(")
                        .append(", ")
                        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
                        .append(")");
        }

        if (funcType <= FUNCTION_I2S) {
            return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("(" + ExprProcessor.getTypeName(
                    TYPES[funcType - FUNCTION_I2L]) + ")");
        }

        //		return "<unknown function>";
        throw new RuntimeException("invalid function");
    }

    @Override
    public int getPrecedence() {
        return getPrecedence(funcType);
    }

    public static int getPrecedence(int func) {
        return PRECEDENCE[func];
    }

    public VarType getSimpleCastType() {
        return TYPES[funcType - FUNCTION_I2L];
    }

    private TextBuffer wrapOperandString(Exprent expr, boolean eq, int indent, BytecodeMappingTracer tracer) {
        int myprec = getPrecedence();
        int exprprec = expr.getPrecedence();

        boolean parentheses = exprprec > myprec;
        if (!parentheses && eq) {
            parentheses = (exprprec == myprec);
            if (parentheses) {
                if (expr.type == Exprent.EXPRENT_FUNCTION &&
                        ((FunctionExprent) expr).getFuncType() == funcType) {
                    parentheses = !ASSOCIATIVITY.contains(funcType);
                }
            }
        }

        TextBuffer res = expr.toJava(indent, tracer);

        if (parentheses) {
            res.enclose("(", ")");
        }

        return res;
    }

    private static VarType getMaxVarType(VarType[] arr) {
        int[] types = {CodeConstants.TYPE_DOUBLE, CodeConstants.TYPE_FLOAT, CodeConstants.TYPE_LONG};
        VarType[] vartypes = {VarType.VARTYPE_DOUBLE, VarType.VARTYPE_FLOAT, VarType.VARTYPE_LONG};

        for (int i = 0; i < types.length; i++) {
            for (VarType anArr : arr) {
                if (anArr.type == types[i]) {
                    return vartypes[i];
                }
            }
        }

        return VarType.VARTYPE_INT;
    }

    // *****************************************************************************
    // getter and setter methods
    // *****************************************************************************

    public int getFuncType() {
        return funcType;
    }

    public void setFuncType(int funcType) {
        this.funcType = funcType;
    }

    public List<Exprent> getLstOperands() {
        return lstOperands;
    }

    public void setImplicitType(VarType implicitType) {
        this.implicitType = implicitType;
    }

    // *****************************************************************************
    // IMatchable implementation
    // *****************************************************************************

    @Override
    public boolean match(MatchNode matchNode, MatchEngine engine) {
        if (!super.match(matchNode, engine)) {
            return false;
        }

        Integer type = (Integer) matchNode.getRuleValue(IMatchable.MatchProperties.EXPRENT_FUNCTYPE);
        return type == null || this.funcType == type;
    }
}